In general, a circuit breaker operates to engage and disengage a selected electrical circuit from an electrical power supply. The circuit breaker ensures current interruption thereby providing protection to the electrical circuit from continuous over current conditions and high current transients due, for example, to electrical short circuits. Such circuit breakers operate by separating a pair of internal electrical contacts contained within a housing of the circuit breaker. Typically, one electrical contact is stationary while the other is movable (e.g., mounted on a pivotable contact arm). The contact separation may occur manually, such as by a person throwing a handle of the circuit breaker. This may engage a trip mechanism, which may be coupled to the contact arm and moveable contact. Otherwise, the electrical contacts may be separated automatically when an over current or short circuit condition is encountered. This automatic tripping may be accomplished by a tripping mechanism actuated via a thermal overload element (e.g., a bimetal element) or by a magnetic element (e.g., an actuator).
Upon separation of the electrical contacts by tripping of the circuit breaker, an electrical arc may be formed. This separation may occur due to heat and/or high current through the circuit breaker. It is desirable to extinguish such arc as quickly as possible to avoid damaging internal components of the circuit breaker. However, in previous circuit breakers, although extinguishment of such arcs has been effective, the arc may not have been extinguished as rapidly as desired. Accordingly, in some designs it may have been needed to make the internal components of the breaker somewhat thicker to account for damage that may occur to them due to the arc.
Accordingly, there is a need for apparatus, systems and methods to better extinguish an electrical arc in a circuit breaker resulting from contact separation.